Increasingly, products are designed using computer aided design (CAD) systems and then manufactured in computer aided manufacturing (CAM) environments. Large engineering projects and complex product designs have increased the need for computer based product related information like CAD designs, CAM instructions and assembly interrelationships. Thus, product designs and related data are being collated on a large scale for storage and processing on computer systems.
A product family consists of products sharing certain common characteristics. For example, all components in a product family used in an aircraft pumping system may share a common “hydraulic system design”. This doesn't mean, however, that all products in the family share the same hydraulic components. The aircraft size determines the individual hydraulic component characteristics of the pumping system, e.g., pump capacity, and the characteristics of its associated components may change, e.g., tubing routes. But the overall hydraulic architecture of the aircraft pumping system remains the same. It is important that a virtual product modeling system be capable of operating on the product “family” as a whole unit.
Ideally, with a large number of products being designed using CAD systems, virtual product modeling should be easily possible. Virtual product modeling can expedite the design process for a family of products sharing an overall product architecture. However, conventional computer systems are unable to capture a critical fraction of the product data for a family of products necessary to perform virtual product modeling. A required degree of flexibility in a virtual product modeling process for modeling a family of products is not feasible with conventional computer systems. Hence, there is a need for a system capable of capturing a critical reusable quantum of product data for a family of products making flexible virtual product modeling feasible.
Customizing a given product from a product family also presents limitations to the designer. A designer can customize a product selected from a product family, which includes many product variants. Manufacturers typically face logistical problems in tracking the information about variants. Typical problems involve tracking which parts are contained in a given variant, determining what technical data is applicable to a given variant, determining how the technical data maps on to a manufacturing plan, and how does a given manufacturing plan account for all the parts in a given engineering design. At present, a designer reconstructs relationships between product design domains either mentally or with some minimal computer support. Manual tracking of such relationships incurs high costs and is prone to errors. Thus, there exists a need for a computer-based system to effectively manage relationships between product design domains.
Methods for defining and managing the relationship of variants to the product family exist. One such method is termed “the effectivity method.” Traditional effectivity defines which parts go into each end product configuration. Presently, the trend in the industry is less and less use of traditional effectivity. Reduced use of effectivity means diminishing the knowledge about what is common among different product designs. Thus, there is a need to capture the knowledge about common characteristics of differing product designs.
When a change is made to a particular product assembly, manufacturing planners get an entirely new assembly definition instead of just the specific changes to that particular product assembly. Manufacturing planners then have to perform significant manual labor to discover the specific minor changes and existing commonality between old and new assembly definitions. This leads to avoidable extra cost in manufacturing planning.
As the industry increasingly uses CAD designs for modeling products, there will be a need to harmonize CAD designs for a product family having numerous variants. Typical CAD systems can model product assembly structure as part of a three dimensional CAD design for a single variant. Such CAD systems cannot share assembly-level structure among several assembly variants. Thus, designers are forced to maintain multiple and independent CAD designs for variants. Multiplicity of variant designs creates an undesirable situation where there are many copies of engineering and bill-of-materials assembly definitions that are similar, but have unique copies of product structure definitions. Thus, there is a need to eliminate multiple and independent drawings, CAD data and product structure for variants.